This application is an improvement upon co-pending U.S. application Ser. No. 474,115, filed May 28, 1974, now U.S. Pat. No. 3,948,750, which is hereby incorporated by reference herein.
The present invention relates to a spacer device for a hollow bipolar electrode fabricated from suitable anode and cathode materials, where the spacer device provides mechanical support and reinforcement within the hollow body and provides an additional electrical current pathway from the anode to cathode. A plurality of bipolar electrodes of the present invention are arranged to form a bipolar electrolytic cell suited for use in processes which involve the electrolysis of alkali metal halides to produce useful products, including alkali metal halates, especially chlorates, alkali metal perhalates, halites and hypohalites. More particularly, sodium chlorate is specifically contemplated for production according to the teachings of the present invention, although other products of the type described are also contemplated within the scope of the present invention. Moreover, the present invention can be used to produce chlorine, hydrogen and alkali metal hydroxide in diaphragm or membrane cells from alkali metal chlorides.
In processes which produce perhalates, halates, halites, and hypohalites, reactions take place which are not electrolytic in nature. Accordingly, two regions or zones are present, namely an electrolysis zone, where most of the electrolytic reactions take place, and a reaction zone, where certain chemical reactions not electrolytic in nature take place. Electrolyte is transferred from the electrolysis zone to the reaction zone, and in some instances, electrolyte is recycled from the reaction zone back to the electrolysis zone. If chlorate is taken as an example of a product produced according to the teachings of the present reaction, the principal reactions taking place in the electrolysis zone are the following: